Photo-tube



Aug. 15, 1933. E WILSON 1,922,185

PHOTO TUBE Filed July 5, 1929 i n 5 g i i 1 a i i g i g INVENTOR ZZr/fl[447500.

1 ATTORNEY UNITED} STATES PATENT ,OVFFI'CEV PHOTO-TUBE" Earl .D. Wilson,Wilkinsburg, Pa., assignor to Westinghouse Electric & ManufacturingCompany, a Corporation of Pennsylvania Application July 5, 1929. SerialNo. 376,115

2 Claims. (01. 250-415) This invention relates to photo-tubes andpar- 15and 16, but insulates them therefrom. Standticularly to the constructionand method of supard 21 extends through an upper press 24, and portingthe electrodes thereof. connects the external metallic cap 25 with theIt is an object of this invention to provide a control grid 26.Preferably, the standard 21 is cathode for a photo-tube of such formthat the offset in order to afford room in the bead 20 for 60 effect ofthe shadow of the other electrodes upon the brace 21 A rod 22 is weldedto standard 21 the cathode shall be minimized. and brace 21 and bead toextend along the control Itis a further object of my invention toprogrid 26 and is secured thereto at numerous points.

vide a photo-tube with a shield grid and a con- During the constructionof the tube, the matrol'grid and to so arrange the supports for theterial for coating the cathode is deposited in a elements that theshield grid Shall be, as far as capsule 27 on the under side of disc 10.This possible, unaffected by any mechanical vibration. material isvolatile. When the tube has been Other objects of my invention anddetails of the pumped and sealed, it is subjected to a highireconstruction willbe apparent from the following quency alternatingelectro-magnetic field which description and the accompanying g, iproduces eddy currents in the metallic parts. 0

which The disc 10, being a closed circuit in eifective Figure 1 isacentral vertical section, and position to be energized by the field,carries rela- V Fig. 2 is a horizontal section. tively heavy eddycurrents and is, consequently,

The photo-tube is y Similar to that S own heated more than the othermetallic elements of in my p dins app Serial ,344, the tube. Thephoto-electric material in the vet filed Fe y 1929, for an p veme t incapsule 27 is thereby evaporated and distills away Shielded anodephoto-tubes, the present applifrom the disc 10, cati n bein r an p v m pthe p o The material will be deposited mainly upon the tube illustratedin S Impending pplication. glass envelope 1, but, as the device isheated,

phbto-tllbe has the usual pa e t in a furnace after this operation, thematerial ve ope provided t the lower w a press distills from the wall 1on to the relatively cool 2 through which extend connections for theancathode 5 By this process, very uniform and Ode the Shield grid 4andthe cathode The readily controlled coating is deposited on the anodeis a vertical centrally located rod which is inner fa of the mm If thecupsule 5 Connected through the press with 3* pin which were on the sideof the disc 10 toward'the cathode,

is one o four pins, pe located 00013628158. the material would distilldirectly from the disc Wlth a standard recelvmg P The shleld on to thecooler cathode and a less even deposit grid 4 is supplemented by a disc'7 at the upper would result end a sleeve 8 at the lower end slmflar mIn the operation of the device, light is received purposfe n cmmictmncorresponding through the opening which extends longitudinally parts insaid copending application.

f the cathode and is reflected from the inner The Shield grid isSupported by a standard by Surface of the cylindrical cathode Thisopenine $215;ifiiiittfiti iiutfiii 1%, threat; of t througnthe press 2and connects the shield grid hollow cylindrical cathode as disclosed inFig. 2. 4 disc '7 sleeve 8 and disc 10 to the external s and in mrefiectmns of the 13 t llghtoccur before 1t again emerges through theThe cathode 5 is in the form of a tube or cyl- The efilect producedinder supported by two uprights 15 and16, which each that hght lmpmges11p0n the i g e connected with standards mounted in the cathode,consequently, the many reflectlons largepress Both uprights extendthrough Openings ly counteract the defect of the presence of opaque inthe disc 10. Thestandard 11, connected to elements, m s the anode e twogrids l upright 15, extends through the press 2 and cond then l-P1 In iay, a Very effective meets the cathode with the external pin 18. AnPhoto-tube 1S provldadl Whlch 15 but Shghtly Sen- 0 "50 other standard19, connected to upright 16, ex- Sitive mechanical J 5 tends into thepress 2 but not through it. Although I have illustrated and describedbut Both uprights extend above the upper end of a single modification,many variations of my the cathode 5 and are there connected by a beadinvention will readily occur to those skilled in 20, which also connectsa standard-21 and a sup the art. The omission of any specificdescription :1, 10 plemental brace 21 together and to the uprights ofthese was not intended as a limitation, the

2. A photo-tube comprising a hollow cylindrical cathode, photo-electricmaterial on said cathode supporting members extending along elements ofthe cathode, a press in which said sup porting members are mounted, asecond press, a support mounted in said second press rigidly connectedto and insulated from said supporting members, and extending within saidcathode and an electrode carried by said support.

EARL D. WILSON.

